Fitting Howa Mini 1500 barreled actions into after market stocks

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  • Sticks
    Chieftain
    • Dec 2016
    • 1922

    Fitting Howa Mini 1500 barreled actions into after market stocks

    When I was fitting the two barreled actions into the two Boyd's Stocks that I picked out, there were dramatic differences in the dimensions for the pillars.

    One fed 4 out of 5 from the magazine, and the 5th needed a fairly slow push from the bolt, or it wold catch the bottom of the feed ramp and lock up. The other shot the nose up so high it would lock up with the nose in the top of the breech. Basically both needed the gap closed up between the bottom metal (plastic) and the action.

    Both Legacy, and their local gunsmith they use and refer to in NV had no numbers for the distance from the bottom of the action to the top of the bottom plate. The gunsmith did state that you did not want direct contact with the top of the magazine well and the receiver - this would lock the bolt up on the magazine - especially when the bolt was pulled back, the magazine would pop up in front of the bolt. Also want one to be careful about torqueing to the 50"#, the bottom plate had a tendency to split right up the seam in the middle.

    Ultimately what I did was make .05" adjustments in the gaps until I got proper feeding with the magazine pushed all the way in, and out (there is some slop - if you are shooting off some bags and resting on the magazine it will push it in deeper) then fine tuning for that edge of function to get a working range.

    The working numbers that I got for the front was .600" to .650" and the rear was 1.125" to 1.170" You still got function if you went longer in the rear, but the nose (123 ELD) was right on the edge of the feed ramps.

    Bear in mind when you torque the action screws down it will compress the plastic a bit. Both rifles were fitted at .125 in the rear but compressed enough that the action screws protruded enough to cause interference with the bolt, so I had to add a brass washer between the bottom plate and the stock to get some clearance.

    I would also like to note that Boyd's stocks are inverted on the angle for the bottom plate. The bottom plate is not parallel with the action (the mag well is, but not the mounting surface). This required milling of the rear behind the trigger guard, which if you have a mill, then this is a piece of easy. Otherwise you are trying to do this with a scraper, dremmel, or other Bubba methods.

    I am going to try to bed the bottom plates to make it as flat as possible to get as much bearing surface for the plastic as I can, even though I did pillar the action screws. Another member here did bore out his bottom plate and put in a machined bushing to go with a better fit and not compress the plastic. If I had a lathe I would go this route, but I don't and the thought of trying to cut a piece of brass bushing down to 5/32 with a dremmel and get a parallel surface does not appeal to me. I had enough fun trying to cut the pillar tubes down and get them square.

    Both stocks needed inletting for the bolt handle, and the barrel on the left side. Nothing major here, then tape wrapped around the barrel until it took minor pressure to drop in the barrel channel to keep it centered in the stock. Both Boyds stocks I took some 6mm bolts (65mm long), cut the heads off, and wrapped some masking tape (blue) around the bolt until they were sung in the pillar sleeves to keep it centered and push any epoxy all the way through. I did forget to put release agent inside the sleeves, so after the first 2 hours of setting, I unscrewed each bolt 1/4 turn, and did this once an hour x3 then what would have been the forth session, I removed them entirely so there would be little to no epoxy inside the sleeves.

    The Aluminum HCR chassis I also had to bed the action in. There was significant play that would actually bind up the magazine and prevent insertion if the action was pushed all the way to the back. I just loosened up the action screws enough to nudge the action back and forth to get the mag centered in the action and made witness marks to locate the action when seating in the bedding compound. I used a couple pieces of para cord with tape wrapped around the end until it was a snug fit in the action screw holes then the modeling clay on top of those (was worried about the pressure of the epoxy pushing the clay out/down.
    Sticks

    Catchy sig line here.
  • usmcm16a2
    Warrior
    • Aug 2015
    • 538

    #2
    I have 2 composite stocks available

    Comment

    • Sticks
      Chieftain
      • Dec 2016
      • 1922

      #3
      Originally posted by usmcm16a2 View Post
      I have 2 composite stocks available
      You mean matching coffee table reading lamps.
      Sticks

      Catchy sig line here.

      Comment

      • flyrod
        Bloodstained
        • Dec 2017
        • 38

        #4
        mounting howa mini receivers

        Hello everyone. I've had a howa mini for some time now, which is how I found this forum. I joined so that I could see some of the pictures that have been posted. My mini is in 223, but I've had a lot of the same experiences reported here: very accurate, good value, mag release is in the wrong place, the plastic stock is not great etc. Anyway, I wanted to share my approach to mounting the mini receiver into a stock.

        As others have mentioned, the actions screws clamp down on the plastic "magazine holder" piece, so if you tighten them much the plastic will start to deform and squish out the sides or possibly crack. The screws can also loosen a bit if the plastic moves. I noticed that the zero would shift somewhat and re-tightening the screws would move it. Additionally, the stocks are not made to clamp the magazine holder square. I saw this with both the boyds and the OEM stock:



        The tool paths are not in the same plane, and the plastic part gets bent as the screws are tightened. I don't know if this is intentional for some reason, but it doesn't seem ideal to me. Thankfully, the action screws are a standard size so I found a couple small bolts, faced the heads, and drilled/tapped them:



        Now the bolts are tightened against aluminum pillars/blocks that are stress free epoxied into the stock, and the magazine holder is simply screwed on top of that. The small screws don't need a lot of torque to just hold the plastic in place. The aluminum height can be worked out from measuring the OEM stock or by just function testing with the assembly done up outside of the stock. As mentioned above, too thick and the bolt may not reliably strip rounds from the mag, and too thin and the bolt may hit the back of the mag. I don't remember what numbers I used, but I think I went a little thinner than the OEM stock.

        So no howa parts are modified and it can be taken apart and reassembled repeatably with no zero shift.
        Last edited by flyrod; 04-17-2019, 03:26 PM. Reason: fixed pictures again

        Comment

        • Lone Hunter
          Warrior
          • Jan 2017
          • 170

          #5
          My Boyds was too thick and I had to dremel out the bottom plastic. It would load 3 rounds but rounds 4&5 it would pick up sometimes but most times not. Once I dremeled it out there was no problem. Like others have stated I had to relieve some on the left side of the barrel channel and in the front of the bolt. I will be making the magazine release mod and magazine mod after deer season. Plus I think pillar bedding and pillars are going to be done also. The only plastic I like are on Glocks.

          Comment

          • Lone Hunter
            Warrior
            • Jan 2017
            • 170

            #6
            Flyrod, I like your ideal. What size bolts and lengths did you use? Your using the nuts as a jam nut that can be adjusted to fit different widths and not torque the plastic down too hard. They make some metal bottom metal but it is real pricey. Keep up the good work.

            Comment

            • Sticks
              Chieftain
              • Dec 2016
              • 1922

              #7
              The bolts are a Metric thread, 6x.75. Howa torque specs are 50 in# on the action screws.

              I am surprised that the factory synthetic stock was also at the wrong plane for the bottom plastic. Might be that the action and the bottom plate both need to be glass bedded. Howa really should come out with an aluminum bottom plate and be done with it. Steel would be nice, but I would think that the forging process for an aluminum cast should be fairly easy.
              Sticks

              Catchy sig line here.

              Comment

              • Lone Hunter
                Warrior
                • Jan 2017
                • 170

                #8
                Originally posted by Sticks View Post
                The bolts are a Metric thread, 6x.75. Howa torque specs are 50 in# on the action screws.

                I am surprised that the factory synthetic stock was also at the wrong plane for the bottom plastic. Might be that the action and the bottom plate both need to be glass bedded. Howa really should come out with an aluminum bottom plate and be done with it. Steel would be nice, but I would think that the forging process for an aluminum cast should be fairly easy.
                I appreciate the info. I would take aluminum bottom in a second over the crappy plastic any day. Wish someone would make it reasonably priced. Plus it would keep the weight down over a steel bottom metal.

                Comment

                • LRRPF52
                  Super Moderator
                  • Sep 2014
                  • 8569

                  #9
                  Welcome aboard. So your bolts torque against the pillars to hold the action and the additional screws just hold the bottom plastic in place independent of the action?
                  NRA Basic, Pistol, Rifle, Shotgun, RSO

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                  Comment

                  • Sticks
                    Chieftain
                    • Dec 2016
                    • 1922

                    #10
                    I like the idea, but trying to counter bore the bottom side to accommodate the thickness of the bolt head and washer, and still have the correct height for the bottom plate to allow proper feeding from the magazine...the front was already thin at .60". Taking another .25 leaving .4 to .35 for a recoil lug seems risky.
                    Sticks

                    Catchy sig line here.

                    Comment

                    • stumpjumper3d
                      Bloodstained
                      • Nov 2017
                      • 25

                      #11
                      If Howa does not fix these problems on the 2018 models it will start affecting sales of the mini action guns.

                      Comment

                      • flyrod
                        Bloodstained
                        • Dec 2017
                        • 38

                        #12
                        Originally posted by LRRPF52 View Post
                        Welcome aboard. So your bolts torque against the pillars to hold the action and the additional screws just hold the bottom plastic in place independent of the action?
                        Exactly. The receiver is well made. It has a flat bottom and everything on mine was straight and square. This made it easy to mill a simple block that engaged the recoil lug and had the proper thickness in front, and turn a simple cylindrical pillar on the lathe for the rear. I could not find anything that would stick to the OEM plastic stock, but the boyds is a wood laminate, so it's easy to modify by cutting and gluing. So the boyds was hogged out and the aluminum glued in using the traditional stress free epoxy bedding techniques.

                        The plastic magazine holder on my howa was not particularly straight, the holes didn't exactly line up with the receiver, etc. So instead of trying to fix it with bushings and make pillars too, I used the receiver and bolts that tighten against machined aluminum to position things. This is repeatable, everything is flat, square etc., the bolts don't come loose. I shoot local matches with it, and I can take it all apart to clean out the dirt and dust, and when it all goes back together the zero is where I left it.

                        Then the magazine holder attaches independently using the two little screws that thread into the back of the bolts. The torque on these is not critical.

                        Sticks: I guess I don't completely understand what you're saying. If you're talking about trying to modify one of the OEM plastic stocks then I think there could be a variety of problems, mostly having to do with getting something to stick to the plastic. My OEM stock did have pillars, but they were pretty sloppy and thin. The receiver and action screws had lots of wiggle room, but could not be reliably tightened. Where the pillars hit the plastic magazine holder, they left a ring impression where they deformed the plastic. On the bottom of the receiver I could see aluminum rings where they were rubbing on the receiver as everything was squirming around. If you're talking about making a short/small pillar to glue into a wood stock, you are right in that the front pillar would be pretty short. This is why I used a block of aluminum that also engages the recoil lug and extends back to the magazine well. The stock is not just counter bored on the bottom, a whole piece is cut out and replaced by the aluminum block. It has plenty of surface area for the glue to connect it to the wood. With my receiver bolted into the stock, if I thunk the barrel it rings. I've successfully used this method on some rifles with serious recoil, so I'm not very worried about it with the mini. I guess I should've taken more pictures of how it went together.

                        Anyway, thanks for the replies guys.
                        Last edited by flyrod; 12-16-2017, 09:42 PM.

                        Comment

                        • Sticks
                          Chieftain
                          • Dec 2016
                          • 1922

                          #13
                          Thank you for the detailed explanation of how you went about this. Clears up some confusion on my end.
                          Sticks

                          Catchy sig line here.

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